Air-cooled engine cooling air distribution housing



Jul 14, 1970 E #ORSTNER ET AL 3,520,283

AIR-COOLED ENGINE COOLING AIR DISTRIBUTION HOUSING 2 Sheets-Sheet 1 Filed June 5, 1968 [Men/0n:

EGO/Y Faun/5k KARL R110 FF July 14, 1970 E. FORSTNER ET AL 3,520,283

AIR-COOLED ENGINE COOLING AIR DISTRIBUTION HOUSING Filed June 5, 1968 2 Sheets-Sheet 2 Fig.

Fig. 1

I In men for:

56 0A! faksr/vs 2 MAR!- 171/016 United States Patent 3 Int. Cl. F011) 1702, 7/02; F02f N04 US. Cl. 123--41.62 Claims ABSTRACT OF THE DISCLOSURE The distribution housing is mounted between the opposite rows of cylinders of an air-cooled engine to receive approximately the upper half of the output of an axial cooling air blower. The upper half of the housing is provided with a semicircular funnel portion directly connected with the housing of the blower and a bottom portion, and the line of connection between the portions being defined by engaging surfaces substantially horizontal and at the height of the blower axis. The housing is substantially V-shaped in plan view with oppositely disposed discharge conduits and is constructed of a polyamide synthetic material.

BACKGROUND OF THE INVENTION In known distribution devices for air-cooled internal combustion engines with several rows of cylinders, particularly oppositely disposed, the working cylinders have cover plates or jackets, or a unilaterally open housing inverted over the cylinders of the engine, for guiding the output of an axial blower. If a partial air stream is branched off, for example to be used for heating the automobile, an aperture in the distribution housing is provided. The quantity of the partial air stream is dependent to a considerable extent upon the excess pressure in the distribution housing. Furthermore, it is known to insert a correspondingly dimensioned ventilating pocket or air collecting pocket for increasing the air flow rate in the distribution housing, which pocket is disposed in the inlet twist of the cooling air behind the blower. Although this results in an increase in pressure, the flow of the cooling air to the cylinders is impaired.

SUMMARY OF THE INVENTION In contrast to the above disadvantageous known arrangements, it is an object of the present invention to provide a distribution housing for the cooling air that allows withdrawal of partial air from the cooling air blower, without interfering with the air flow to the cylinders of the engine.

In accordance with the present invention, the above objective is accomplished by providing the distribution housing as a bipartite construction consisting of an upper part or portion and a lower part or portion, connected together along a separating line defined by engaging surfaces that extend approximately horizontal at the height of the axial cooling air blower axis. These parts are connected to each other in a substantially V-shape in plan view to form two discharge conduits for branching off partial streams of air from the cooling blower. Thereby, the gentle air flow is maintained while air is conducted directly from the cooling blower to the individual working cylinders and the discharge channels are supplied with a partial air stream. Consequently, a correspondingly large quantity of air is available at a suflicient pressure and sufficient amount to serve as the fresh air for the heating of the automobile, for example, or for ice defrosting the rear window or windshield of the automobile. Also, or in the alternative, the partial air stream can be employed to cool encapsulated vehicle brakes or for cooling the transmission fluid of the automobile automatic transmission. Throughout the specification, including the claims, the term cooling air has been used for convenience, although it is understood that this air may be used above with respect to being withdrawn by the housing discharge conduits for any of the above uses, for example, which include both heating and cooling.

A partially spatially favorable arrangement of the distribution housing is obtained when the upper part of the housing comprises a semicircular inlet funnel partially surrounding the cooling air blower, which funnel terminates in V-shaped legs covering the cylinders; these legs form, together with the V-shaped lower part legs, tubular discharge conduits extending generally in the axial direction of the cooling air blower for withdrawing the cooling air for the auxiliary uses mentioned above. This ensures simultaneously an extensively undistributed air flow. A uniform distribution of air into the individual discharge conduits is obtained by dimensioning the effective through-flow cross sectional area of the conduit disposed in the inlet twist of the cooling air in the distribution housing behind the inlet funnel smaller than the throughflow effective cross sectional area of the oppositely positioned discharge conduit. Preferably, the upper and lower parts of the distribution housing are each formed of single piece synthetic shelves, which may be glued or otherwise bonded together along their engaging surfaces.

BRIEF DESCRIPTION OF THE DRAWING Further objects, features and advantages of the present invention will become more clear from the following detailed description of the drawing, wherein:

FIG. 1 is a cross sectional view through the distribution housing for an air-cooled internal combustion engine having conventional parts shown in dot-dash lines, which housing is provided with discharge conduits for withdrawing a partial amount of the air supplied by the blower for auxiliary uses, the cross section being taken perpendicular to the crankshaft axis and axis of the blower;

FIG. 2 is a side elevation view of the distribution housing according to FIG. 1, on a reduced scale; and

FIG. 3 is a top plan view of the distribution housing according to FIG. 2.

DETAILED DESCRIPTION OF THE DRAWING As shown in FIG. 1, the crankcase 1 of the air-cooled internal combustion engine is provided on its opposite sides with generally horizontally extending cylinder rows 2, 3, respectively, of which only the end working cylinders 4, 5 are illustrated. The working cylinders 4, 5 are cooled by air supplied from an axial blower 6, of conventional construction and illustrated in dot-dash lines in the drawing. The axial blower 6 is provided at the level of the upper side 7 of the crankcase 1 on the front face of the engine and is driven by the engine in a conventional manner through a belt drive, not shown.

A distribution housing 8 for the cooling air is in communication with the axial blower 6 and covers the cylinder rows 2, 3. The distribution housing 8 consists of a dish-like upper housing part 9 and a dish-like lower housing part 10, which are connected with each other along a parting line formed by their engaging surfaces, which extend generally horizontally at approximately the same height as the axis of rotation 12 of the axial blower 6. The housing parts '9 and 10 are provided with flanged rims 13- forming the engaging surfaces along the parting line 11, which rims 13 are provided with a plurality of lugs or projections 14 for securely fastening the distribu tion housing 8 to the upper side 7 of the crankcase, or

to the cylinder heads of the working cylinders 4, 5 by suitable threaded fasteners, for example.

The upper part 9 of the distribution housing 8 is provided with a semi-circular inlet funnel concentric with respect to the axis of rotation 12 of the axial blower, which funnel terminates in legs 16, 16 providing the upper part 9 with a generally V-shape in plan view as shown more clearly 11 FIG. 3. The legs 16, 16 of the upper part 9 form, together with the likewise V-shaped lower housing part 10, discharge conduits 17, 18, respectively, for conducting a partial stream of air branched off from the axial blower. For guiding the partial air stream to the individual discharge conduits 17, 18, a tongue or baffle 19 is aligned with the axis of rotation 12 of the axial blower 6 in downstream alignment with the inlet leading edge 20 of the lower housing part 10. The tongue 19 is connected with the inner side of the upper housing part 9. The discharge conduits 17, 18, have a flat through-flow cross section in the zone of the inlet edge 20 (FIG. 1) and terminate toward their free ends 21, 2 1' as tubes provided with connecting flanges 22. The through-flow effective cross sectional area of the discharge conduit 18 disposed in the inlet twist of the cooling air is smaller than the comparable effective through-flow cross sectional area of the discharge conduit 17. The upper housing part 9 and the lower housing part 11) of the distribution housing 8 each consist of a heatinsensitive or heat-stable synthetic material from the class of polyamides.

When the engine is running, the lower half of the cooling air conveyed by the axial cooling air blower 6 in the direction of flow indicated by arrow S in FIG. 2 is conducted along and underneath the underside 23 of the lower housing part 10 to the individual cylinders 4, 5, whereas the upper portion of the cooling air, separated by the inlet funnel 15 and the leading inlet edge 20, flows into the discharge conduit 17, 18. With such an arrangement, the full dynamic pressure of the axial cooling air blower 6 is available for each of the partial air streams in the respective ducts 16, 17. In addition to the effective cooling of the working cylinders 4, 5, there remains a sufficiently large supply of air to be branched off by means of the discharge conduit 17, 18 for heating or cooling the automobile, or for other auxiliary purposes without contacting the cylinders.

The conventional portions of the combination according to the present invention have been set forth in dotdash lines only to prevent the novel self-combinations from being obscured; these conventional portions may assume any suitable construction. Further modifications, variations and embodiments of the invention are con-- templated within the spirit and scope of the invention.

We claim:

1. An air-cooled internal combustion engine, comprising: a crankshaft; at least two rows of cylinders disposed on opposite sides of said crankshaft; an axial cooling air blower provided with an axis of rotation substantially parallel to said crankshaft axis; a distribution housing disposed above and between said rows of working cylinders; said distribution housing having an upper housing part and a separate lower housing part each having engaging surfaces extending approximately horizontally and generally at the height of said axis of rotation of said cooling air blower; said distribution housing having at least two discharge means for conducting cooling air directly from said axial cooling air blower away from said working cylinders.

'2. The engine according to claim 1, wherein said distribution housing consists of said upper part and lower part, each being a single piece shell of a polyamide synthetic material; said upper and lower parts being bonded together along said engaging surfaces.

3. The engine according to claim 1, wherein said discharge means are each tubular and terminate downstream in annular connecting flanges.

4. The engine according to claim 1, wherein said distribution housing is mounted directly above and over said rows of cylinders.

5. The engine according to claim 1, wherein said distribution housing has a substantially semicircular inlet portion; said axial blower having a housing provided with a semicircular portion axially aligned with and connected to said distribution housing semicircular portion for passing therethrough the upper half of said axial blower output; said distribution housing having a lower plate directing the lower half of said axial blower output downwardly toward said cylinder rows; said lower plate having a leading edge, with respect to the direction of air flow, axially spaced a substantial distance from the leading edge of said distribution housing semicircular portion.

6. The engine according to claim 5, wherein said lower plate leading edge is substantially V-shaped pointing away from said axial blower.

7. The engine according to claim 1, wherein said upper housing part of said distribution housing comprises an inlet funnel partially encompassing said axial cooling air blower; said funnel terminating in two legs diverging away from said funnel to provide said upper part with a V-shape in plan view; said upper part legs extending over and covering said rows of cylinders, respectively; said lower distribution housing part being of V-shape in plan view and having cooperating legs forming with respective legs of said upper part two tubular conduits constituting said discharge means extending in the axial direction of said cooling air blower.

8. The engine according to claim 7, wherein said distribution housing consists of said upper part and lower part, each being a single piece shell of a polyamide synthetic material; said upper and lower parts being bonded together along said engaging surfaces.

9. The engine according to claim 7, wherein one of said tubular conduits that is disposed in the inlet twist of the cooling air in the distribution housing downstream of said inlet funnel has an elfective through-flow cross sectional area substantially smaller than the corresponding effective through-flow cross sectional area of the other of said air channel means- 10. The engine according to claim 9, wherein said upper part and said lower part are each formed of a single piece shell of polyamide synthetic material; said upper and lower part being secured to each other by bonding along said engaging surfaces.

References Cited UNITED STATES PATENTS 2,893,361 7/1959 Badertscher 1234l.6 2,980,194 4/1961 Porsche 1234l.6 1,386,381 8/1921 Taggard 12341.58 1,890,745 12/1932 OConnor 12341.58 2,159,599 5/1939 Morrison 1234l.55 2,476,643 7/1949 Wald 12341.59

MARK NEWMAN, Primary Examiner US. Cl. X.R. 

